Change 'from_bytes_until_nul' to const stable

This commit is contained in:
Trevor Gross 2023-01-30 18:11:03 -05:00
parent 83b05ef0ee
commit 877e9f5d3a
2 changed files with 14 additions and 4 deletions

View File

@ -320,8 +320,9 @@ fn strlen_rt(s: *const c_char) -> usize {
/// assert_eq!(c_str.to_str().unwrap(), "AAAAAAAA");
/// ```
///
#[rustc_allow_const_fn_unstable(const_slice_index)]
#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
#[rustc_const_unstable(feature = "const_cstr_from_bytes_until_nul", issue = "95027")]
#[rustc_const_stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
pub const fn from_bytes_until_nul(bytes: &[u8]) -> Result<&CStr, FromBytesUntilNulError> {
let nul_pos = memchr::memchr(0, bytes);
match nul_pos {

View File

@ -16,25 +16,29 @@
/// bytes where the borrow propagated all the way to the most significant
/// bit."
#[inline]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn contains_zero_byte(x: usize) -> bool {
x.wrapping_sub(LO_USIZE) & !x & HI_USIZE != 0
}
#[cfg(target_pointer_width = "16")]
#[inline]
#[cfg(target_pointer_width = "16")]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn repeat_byte(b: u8) -> usize {
(b as usize) << 8 | b as usize
}
#[cfg(not(target_pointer_width = "16"))]
#[inline]
#[cfg(not(target_pointer_width = "16"))]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn repeat_byte(b: u8) -> usize {
(b as usize) * (usize::MAX / 255)
}
/// Returns the first index matching the byte `x` in `text`.
#[must_use]
#[inline]
#[must_use]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
pub const fn memchr(x: u8, text: &[u8]) -> Option<usize> {
// Fast path for small slices.
if text.len() < 2 * USIZE_BYTES {
@ -45,6 +49,7 @@ pub const fn memchr(x: u8, text: &[u8]) -> Option<usize> {
}
#[inline]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn memchr_naive(x: u8, text: &[u8]) -> Option<usize> {
let mut i = 0;
@ -60,6 +65,10 @@ const fn memchr_naive(x: u8, text: &[u8]) -> Option<usize> {
None
}
#[rustc_allow_const_fn_unstable(const_cmp)]
#[rustc_allow_const_fn_unstable(const_slice_index)]
#[rustc_allow_const_fn_unstable(const_align_offset)]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn memchr_aligned(x: u8, text: &[u8]) -> Option<usize> {
// Scan for a single byte value by reading two `usize` words at a time.
//